What this snippet does
Global augmentation only works inside ES modules; in a script file, TypeScript throws an error because there are no top-level imports/exports.
Expected output
Compile Error: Augmentations for the global scope can only be directly nested in external modules or ambient module declarations.
Why practise typing this
Typing global scope code builds muscle memory for the symbols and indentation TypeScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
More TypeScript practice
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- Defining an array of numbersBasic Types · beginner